Uterocervical angle at 20 weeks: A promising predictor of spontaneous preterm birth in twin pregnancies

To compare the performance of uterocervical angle (UCA) and cervical length (CL) measurement at 20 weeks of pregnancy for prediction of spontaneous preterm birth (sPTB) in twin pregnancies.

We conducted a retrospective cohort study of 424 twin pregnancies who delivered in our center from October 2014 to December 2018 and who underwent transvaginal ultrasound between 19⁺⁰-22⁺⁰ weeks to measure CL during routine second trimester scan. Recorded ultrasound images of CL were reassessed to evaluate UCA. Medical and obstetric data were also collected for statistical analysis.

A total of 424 women were included. The rates of sPTB rate below 28, 32 and 34 weeks of gestation were 2.8 %, 5.4 % and 10.4 %, respectively. ROC curves showed a better area under the curve (AUC) for UCA at all gestational ages compared with CL (AUC for sPTB <28 weeks 0.902 (p < 0.001) vs 0.620 (p 0.175); AUC for sPTB <32 weeks 0.740 (p 0.001) vs 0.620 (p 0.058); AUC for sPTB <34 weeks 0.676 (p 0.001) vs 0.632 (p 0.047). UCA > 120 degrees was significantly associated with sPTB <28 weeks (p < 0.001; OR 39.17; CI 4.81-319.23; NPV, 99.65 %), <32 weeks (OR 4.23; p 0.002) and <34 weeks of gestation (OR 2.66; p 0.01).

In our study, an UCA > 120 degrees allowed to identify those women with twin pregnancies at risk of sPTB and performed better than CL measurement.